Well first off if you really are interested in Patent law and you have an engineering degree you may be able to avoid law school all together and take the Paten Bar here is the link for it http://www.uspto.gov/ip/boards/oed/exam/registration.jsp . You will be able to do engage in patent law disputes, but not licensed to practice in other areas, but if you truly are interested in patents law and nothing else this may be a way to avoid spending a lot of time & money unnecessarily.

In regards to your specific question you can get into a number of law schools with a 2.86 and there is no "required" GPA, but a 1.2 is not going to cut it. You can see where you stand a chance at certain schools by looking at lawschoolnumbers.com a 2.86 and a 160 LSAT will provide you with plenty of law school options, but Harvard and Yale will not be on the list, but you can have a successful legal career from any ABA law school.